Surface-treating apparatus

ABSTRACT

A system for treating or working on the surface of vehicles, such as airplanes. It is provided with a vertically extensible mast mounted on a carriage for movement relative to the aircraft to be serviced, or at a fixed location depending on the requirements of the job. Two generally horizontally extending extensible booms are swivelly connected to the upstanding arms of a yoke on the top of the mast. Each boom is provided with an underwing high level counterpoise mechanism for maintaining a boom in a desired operating position, and also to serve as means for minimizing the effort required by an operator while working on the surface of an airplane. The forward end of each extensible portion of each boom mounts a surface-treating machine which can operatively support selected types of cleaning, and polishing brushes and applicators which may be needed for the work to be done. These machines are relatively light in weight and are provided with rotating brush supporting spindles so designed that the cleaning and polishing brushes and other tools which may be detachably used in the machine can efficiently be operated over large areas of the surface being worked on. Fluid under pressure, preferably compressed air, is used for raising and lowering the mast, delivering fluid to the cleaning and polishing machines, and for driving the air motors of the machines for rotating their brush and applicator supporting spindles. Suitable valves and conduits effect the desired continuous supply of compressed air to the system. A constant lead and supply line is maintained as a carriage is moved to different areas of the aircraft surface thereby eliminating drag and crisscrossing of lines due to the provision of reeling apparatus on the carriage which maintains the air lines at all times under control.

United States Patent llahian et al.

3,6d8fil6 Mar. M, W72

SURFACE-TREATING APPARATUS George Habian, Manhasset; Franklin, Bayside, both of NY.

Garsite Products, Inc., New York, NY.

Aug. 25, 1969 Inventors: Edwin Assignee:

Filed:

Appl. No.:

[30] Foreign Application Priority Data [56] References Cited UNITED STATES PATENTS 3,104,406 9/1963 Rhodes ..l5/2l R 3,439,372 4/1969 Collier ..l5/2l E 3,460,177 8/1969 Rhinehart et al ..l5/2l E Primary ExaminerEdward L. Roberts Attomey-Philip D. Amins ABSTRACT A system for treating or working on the surface of vehicles,

such as airplanes. It is provided with a vertically extensible mast mounted on a carriage for movement relative to the aircraft to be serviced, or at a fixed location depending on the requirements of the job. Two generally horizontally extending extensible booms are swivelly connected to the upstanding arms of a yoke on the top of the mast. Each boom is provided with an underwing high level counterpoise mechanism for maintaining a boom in a desired operating position, and also to serve as means for minimizing the effort required by an operator while working on the surface of an airplane. The forward end of each extensible portion of each boom mounts a surface treating machine which can operatively support selected types of cleaning, and polishing brushes and applicators which may be needed for the work to be done. These machines are relatively light in weight and are provided with rotating brush supporting spindles so designed that the cleaning and polishing brushes and other tools which may be detachably used in the machine can efficiently be operated over large areas of the surface being worked on. Fluid under pressure, preferably compressed air, is used for raising and lowering the mast, delivering fluid to the cleaning and polishing machines, and for driving the air motors of the machines for rotating their brush and applicator supporting spindles. Suitable valves and conduits effect the desired continuous supply of compressed air to the system. A constant lead and supply line is maintained as a carriage is moved to different areas of the aircraft surface thereby eliminating drag and crisscrossing of lines due to the provision of reeling apparatus on the carriage which maintains the air lines at all times under control.

17 Claims, 13 Drawing Figures PMENTED MAR w m2 3 g SHEET 1 or 5 m 25i Q J 56 479 M y 1 2g W i' INVENTORS.

i 1. 12 "I GEORGE HABIAN 5 58 p 1 EDWIN FRANKLIN ATTORNEY.

PAIENTEDMAR M I972 SHEET 2 UF 5 w 2. L O on Q. g; cm. r E m: m 3 Nb INVENTORS. GEORGE HABIAN EDWIN FRANKLIN ATTORN EY PATENTEDMAR m m2 SHEET 3 [1F 5 INVENTORS. GEORGE HABIAN EDWIN ATTORNEY.

SURFACE-TREATING APPARATUS Aircraft with clean exterior surfaces are highly desired not only by commercial airlines, but also by the military and private plane owners. Accumulations of dirt, oxides and other foreign matter on such surfaces of airplanes cut down their speed, maneuverability and efficiency, and, therefore, add appreciably to operating costs. Experience has shown that one of the most expensive and time consuming aircraft maintenance problems lies in the removal of foreign matter and the cleaning and/or polishing of their exterior surfaces.

Heretofore, the application of cleaning and/or polishing compounds, and the removal of oil, grime and other foreign matter has been done manually with handmops and rags, or a combination of mops, rags and hand held bonnet buffers, which at best afforded only uncertain manual control of polishing pressures. The man-hours spent in preparing or cleaning the aluminum surfaces and polishing them has made this operation an inefficient and costly one. Furthermore, with the evolution of the present day huge aircraft now in use, and the ever increasing size of those about to come into service, such manual methods and means are entirely unsuitable and for obvious reasons must be discarded. While reference has been made primarily to treating aluminum surfaces of aircraft, it will be appreciated that similar problems arise in connection with painted aircraft. In fact many commercial airlines paint part or all exterior surfaces of their aircraft, which also must be treated as in the case of unpainted airplanes.

In short, highly polished, brightly gleaming aircraft are most desired and are the goal of all commercial airline operators, the military, executive and private owners. The main drawback heretofore in achieving these goals, especially for com mercial airlines, has been the prohibitive number of manhours and high utilization factor of their airplanes, which does not allow adequate downtime in which to complete a thorough cleaning and/or polishing job before the aircraft must go back to the flight line. It is believed that with the means heretofore available, no satisfactory system or apparatus has been capable of doing the required work in a minimum of time such that the problems of reduction of man-hours and rapid turn around can be avoided.

The present invention constitutes a solution to the problems discussed above. The system is one which meets the exacting requirements of mechanical cleaning and/or polishing of aircraft with pressure control of the mechanism working on their surfaces such that the aircraft skin is not subjected to over heating. The apparatus is trouble free and economical in operation. The supporting carriage for the apparatus enables it to be wheeled around relative to an aircraft and be positioned wherever needed in order that one or two operators using one system or apparatus can efficiently work'on large adjacent areas of the surface with a minimum of effort, and wash, or apply cleaning or polishing fluids thereon by means of the work unit or machine carried by the free end of elevated booms from a remote source mechanically. This construction insures the removal of dirt and grime, and makes it possible to clean and/or polish the aircraft surface in a straight line, which is, therefore, free of swirl marks regardless of the direction of movement of the cleaning or polishing brush of the support unit.

The number of surface-treating systems or apparatuses employed will depend upon the size and type of aircraft to be serviced, extent of surface to be worked on, and the allowable time in which the work must be done. It will be apparent that one or several can be used at the same time, thereby markedly decreasing the downtime prior to turn around of the aircraft.

It is an object of the invention to provide a novel system or apparatus for mechanically treating the surfaces of vehicles, such as aircraft in order to remove dirt, oil, grime and other foreign matter therefrom and polish the surface so treated.

The invention further consists in the provision of novel apparatus for removing unwanted foreign material from the surface of aircraft by means of mechanism which positions one or more surface-servicing machines or units at any desired operating level which may be required relative to the exterior of the airplane to be serviced, and wherein these machines or units are supported in counterpoised relationship relative to the aircraft such that underwing and vertical surfaces can be serviced with the expenditure of a minimum of effort by the operators.

The invention also consists in the provision of a novel apparatus for cleaning and/or polishing the exterior surface of an aircraft which includes a vertically movable extension mast supporting one or more generally horizontally extending extensible booms, each of which carries a detachably mounted unit for use in washing the surface with or without the use of detergents, applying cleaning fluids to the surface to be cleaned under pressure, and polishing the cleaned surface, and wherein a counterpoise mechanism is provided for supporting the weight of such units when servicing underwing and vertical surfaces.

It is a further object to provide a novel vehicle surface treating and maintenance system which includes a vertically extending telescopic mast having a cross yoke at the top which swivelly mounts two generally horizontally extending booms, each provided with a surface-servicing machine, and compressed air conduits for supplying fluid cleaning compounds or water with or without detergents to the brushes and applicators of the servicing machines or units and for driving the motors which rotate these brushes and applicators, and for effecting the raising and lowering of the mast in order to position the servicing machines and units in locations required for working on the surface of an aircraft.

The invention also consists in the provision of a novel surface-servicing machine having driving spindles and fluidoperated means therefor which mount the cleaning and/or polishing brushes in such manner that their ends are substantially cantilevered supported and wherein the ends thereof can be used efficiently in cleaning and polishing surface areas heretofore most difficult to reach with means heretofore available.

Other objects and features of the invention will appear as the description of the particular embodiment selected to illustrate the invention progresses.

In the accompanying drawings which form a part of this specification, and in which like characters of reference and numerals indicate the same or like parts:

FIG. I is a perspective view of a preferred form of the invention.

FIG. 2 is a side view of a surface-treating or servicing machine boom embodying the invention.

FIG. 3 is a view taken on line 33 in FIG. 2.

FIG. 4 is a plan view of the structure shown in FIG. 2.

FIG. 5 is a somewhat diagrammatic view showing the manner in which a surface-treating machine or unit embodying the invention is connected to the free end of a support boom.

FIG. 6 is a side elevation, partly in section, of a preferred form of surface-treating or servicing machine or unit constructed in accordance with the invention.

FIG. 7 is a top plan view of the structure shown in FIG. 6.

FIG. a is a view taken on line fii8 in FIG. 6.

FIG. 9 is a view taken on line 9-9 in FIG. 6.

FIG. I0 is a view taken on line ]l0 III in FIG. 6.

FIG. Ill is a view taken on line II II in FIG. 10.

FIG. 12 is a view taken on line 12-12 in FIG. 7, and

FIG. 13 is a view taken along line I3I3 in FIG. 12.

With reference to the drawings, the invention consists of a novel surface-treating or servicing system or apparatus for cleaning and/or polishing the exterior surfaces of a vehicle, such as an airplane. It can be mounted on a carriage for movement to selected working locations adjacent to an aircraft being serviced, or it can be fixedly mounted on rigid supports in which case the aircraft to be worked on must be moved into such position that the surface-treating mechanisms of the system can be used in doing the required cleaning and/or polishing work.

In the embodiment selected for purposes of illustration, the apparatus is designated generally 2 (FIG. 1). A'movable carriage 4 supports a vertical mast designated generally 6. This mast is formed with a fixed or lower section 8 suitably mounted on platform of carriage 4. At least one extensible or telescopic section 10 is slidably supported in section 8. Section 10 is mounted for vertical up and down movement in section 8 in any suitable conventional manner. Its movement is effected and controlled by fluid means, such as compressed air, described more fully hereinbelow.

A yoke or transverse boom support 16 is mounted in T-relationship with mast 6 in a bracket 17 attached to the to the top of section 10. Each end of boom support 16 is provided with an upstanding arm (FIGS. 1 and 2). The upper end of each arm 18 carries a suitable-type swivel joint 20 which supports a boom bracket 22 for horizontal swinging movement of a boom 24, described below, to and from the operator. Bracket 22 also is provided with a swivel joint 26 of conventional construction which supports a boom 24 for up and down movement. The mounting arrangement for each boom 24 make it possible for an operator to move it in any desired path of travel while cleaning and/or polishing the surface of an airplane.

A system embodying our invention preferably is provided with two operating booms designated generally 24. Each boom 24 supports a surface-servicing machine or unit M on its free end. We have found that two operators form an excellent work team. In servicing the surface of an airplane, especially one of the present day large aircraft now in use commercially, the greatest efficiency in removing foreign materials from the surface thereof can best be effected by the use of several systems constructed as shown in FIG. 1. If each system be considered a battery, when several batteries are used the downtime which is most important can be held to a minimum.

Since all booms 24 are the same in construction and operation, only one is described herein in detail. Referring to FIGS. 1, 2 and 4, a boom 24 comprises a fixed tubular section 28 having an end flange 30 secured to flange 32 on boom connector 34 swivelly mounted in swivel joint 26. An elongated telescopic or extensible boom section 36 is slidably supported in bushings 38 and 39 in section 28 for reciprocatory movement relative thereto as an operator moves unit M carried thereby as he works on portions of the aircraft being serviced.

The free end of telescopic section 36 is provided with a flange 40 to which is attached a flange 42 of the surface-treating or servicing machine support mechanism 44, described hereinbelow more in detail. Manifold 46 suitably attached to the tops of flanges 40 and 42 has ports 48 and 50 to which are secured conduits or pipes, such as any suitable pressure hose, 52 and 54 through which pressurized fluid, e.g., compressed air and desired surface-treating and servicing fluids can be delivered to a machine M for the work to be done.

Referring to FIG. 1, two flexible conduits 56 and 58 of suitable pressure bearing hose or the like, extend upwardly from platform 5 of carriage 4. The upper ends of these conduits are attached to transversely extending pipes 60, 62, respectively, which are in turn connected to flexible pressure hoses or conduits 64,66, respectively. There are two conduits for each boom 24. Conduits 56,60 and 64 supply pressurized air to other conduits which deliver it to machines or units M carried by support mechanism 44. Conduits 58,62 and 66 are used to conduct cleaning and/or polishing fluids under pressure, or water with or without detergents to other conduits which deliver to the spray nozzle of units M, as described more in detail hereinafter.

Flexible conduits or hoses 56 and 58 can be of any conventional self-storing type. In this way these conduits assume the compact stored appearance and position as shown in FIG. 1, and thereby are free from tangling, damage, etc., during movement of the apparatus from one location to another and while it is in use. The upper ends of conduits S6, and 58 are connected to transverse pipes or conduits and 62. Preferably the upper end of hose 56 is connected through a conventional type of lubricator 57 (FIGS. 2 and 4) mounted on bracket 59 attached to mast section 10.

Compressed air is delivered by pressure hose 12 from a suitable source of supply S. This compressed air is responsible for the following operations: Operating the fluid motors of the units or servicing machines M; effecting the flow of fluid materials to units M, and for raising and lowering mast section 10.

As shown in FIG. 1, hose 12 is wound on a reel R carried by platform 5. This arrangement allows hose 12 to be reeled or unreeled as the case may be when the apparatus embodying the invention is moved from place-to-place during the servicing of the surface of an aircraft. Air hose 12 is connected to a manifold 13 suitably mounted on platform 5. Compressed air is delivered to the motors of units M from manifold 13 through conduit 21, manually operated valve 23, conduits 56,60, 64 and 78 to delivery pipe 52 in manifold 46. Compressed air is delivered from manifold 13 by conduit 25 through manually operated valve 27 and conduit 29 to container 68. From container 68 fluid material, e. g., a selected suitable type of cleaning compound to be used in cleaning the surface of an airplane is delivered under pressure through conduits 58, 62, 66 and to pipe 54 in manifold 46.

Compressed air for raising and lowering mast section 10 is delivered to manually operated two way control valve 14 from manifold 13 through conduit 11. Conduits or pressure hoses l5 and 19, respectively, are provided for conducting compressed air to the top and bottom of the piston (not shown) of telescopic mast section 10 in order to raise or lower it in its tubular fixed support section 8. Movement of valve handle 9 (FIG. 1) up or down effects the desired flow of compressed air through valve 14 to control the direction of movement of mast section 10. When handle 9 is in a substantially horizontal position, movement of section 10 is stopped. Thus, the height of booms 24 relative to the vehicle being serviced can be controlled by the operator, as desired.

Referring to FIGS. 2 and 4, conduits 64 and 66 extend along fixed boom section 28 of boom 24. The rear or left ends of these conduits, as viewed in these figures, are supported in brackets 72 attached to fixed boom section 28. Their front ends, as viewed in the same figures, are secured to rigid pipe coupling members 74, and 75, respectively, mounted in brackets 76 attached to boom section 28.

In order to provide for telescopic movement of boom section 36 relative to fixed section 28, conduits 64 and 66 are continued as conduit sections 78 and 80, respectively, from the tops of members 74 and 75 around lower and upper pulleys or sheaves 82 and 84, respectively, and then back in parallel relationship relative to fixed boom section 28 and conduits 64 and 66, to manifold 46 where they are connected to pipes or conduits 52 and 54, respectively.

Pulleys 82 and 84 are rotatably mounted on a common shaft 86 supported in bracket 88 (FIGS. 2 and 4) positioned above boom 24. Bracket 88 is formed with two longitudinally spaced sets of depending legs 90, each of which has a longitudinal bore seating a conventional type of ball bushing 92. Longitudinally extending parallel guide rods 94 are mounted on each side of boom 24 and extend through ball bushings 92. This construction insures a rolling, low friction movement of bracket 88 along rods 94 is response to the back and forth or in and out travel of telescopic boom section 36 as an operator moves a unit M upon the work during the operation of the apparatus.

The ends of guide rods 94 are suitably supported in brackets 72. If desired sheet metal or plastic guard means, attached to brackets 72 and 76, and designated generally 96 can be provided. These form no part of the invention, and further description or showing thereof is deemed to be unnecessary.

Sagging of hoses 78 and 80 relative to boom 24 and each other which might interfere with the satisfactory operation of the apparatus is prevented by means of a torsional spring device 98, which can be of any suitable design. This device is mounted on bracket 100 secured to boom section 28, and is operatively connected by cable 102 to bracket 88. As boom section 36 moves relative to boom section 28, bracket 88 also is moved on its guide rods 94. Since the front ends of hoses 78 and 80 are attached to manifold 46, when an operator grips a machine or unit M and moves it into working position relative to the surface to be serviced, the outward movement of boom section 36 resulting therefrom will cause bracket 88 to be pulled to the right, as viewed in FIGS. 2 and 4, by hoses 78 and 80 in response to such movement, and sheaves 82 and 84 will rotate as these hoses track thereover. When the operator moves boom section 36 in opposite direction or releases his grip on a machine M, the mechanism just described tends to effect the return of boom section 36 to the position shown in FIGS. 2 and 4. These operations of spring device 98 through cable 102 exert a resilient torsional force on bracket 88 both during the outward and inward travel of boom section 36, and maintain the proper arrangement of hoses 78 and 80 at all times.

A boom counterpoise, of any suitable known design, such as an OPW Spring Balance Unit, manufactured by the Dover Corporation, Cincinnati, Ohio, is provided to support the weight of the surface-servicing unit or machine M, especially when underwing and vertical exterior surface areas of an aircraft are being worked on. In addition this mechanism maintains each boom 24 in a generally horizontal position such that the unit M carried thereby is well within the reach of an operator who need exert a minimum of physical effort in moving the boom to and from himself as he works on the surface being treated.

Each counterpoise unit 184 is mounted on a bracket 22 on mast section 10. It comprises a torsion spring 106 encircling shaft 1118 supported in brackets 110 which form a part of the unit in such manner that when crank 112 fixed to shaft 108 is rocked through link 114 attached to collar 116 secured to boom section 28, tension in spring 1116 caused thereby tends to effect the return of boom 24 to and maintain it in its generally horizontal position shown in FIG. 1.

Under operating conditions when boom section 36 is extended from retracted to fully extended position, an auxiliary counterpoise mechanism is provided to balance boom 24. As boom section 36 is extended outwardly or retracted, the auxiliary counterpoise mechanism operates as described hereinafter to maintain a constant balance at all times. This mechanism is designated generally 118. It can be of the type known as Negator B Spring Motor, manufactured by the Hunter Spring Division of Amatek, Inc., Hatfield, Pennsylvania.

Referring to FIG. 2, Negator mechanism 118 comprises a spring motor 128 mounted on bracket 122 attached to fixed boom section 28. A roller 124 carried by bracket 122 located beneath telescopic boom section 36 supports it for movement relative to boom section 28 during operation of the apparatus. A cable 125 connected to the spring motor of auxiliary counterpoise mechanism 118 extends through an opening in bracket 126 fixed to the underside of boom section 28, and is secured to arm 127 of a weight-containing carriage 128 slidably carried on guide rod 138, the ends of which are supported in brackets 126, 132 secured to boom section 28. There are two longitudinally spaced arms 127, 129 formed on the top of carriage 128 which are provided with conventional ball bushings for providing free, low friction rolling of carriage 128 along rod 136. A cable 136 having one end connected to arm 129 of carriage 128 runs over a pulley 138 freely rotatably mounted on rod 130. Its other end extends through aligned openings in carriage 128 and is attached to the depending flange of bracket 148 secured to the free end of telescopis boom section 36.

The quantity of weights in carriage 128 will depend upon the amount required to insure that even when boom section 36 is fully extended, its boom 24 will always be properly balanced and assume a generally horizontal position when the operator releases his hold on a machine or unit M. This arrangement adds to the complete maneuverability of the entire boom system with the minimum of expenditure of effort on the part of the operator. The operation is such that as a boom section moves outwardly (to the right as viewed in MG. 2) weight carriage 128 will be moved in the opposite direction against the constant resilient torque of the spring motor of mechanism 118, thereby balancing the entire boom system to the extent desired for optimum operation of the apparatus. it will be readily apparent that the movement of weight carriage 128 and the counterbalancing effect of the auxiliary counterpoise mechanism 118 occurs in response to the in or out movement of boom section 36 in fixed section 28.

As mentioned hereinabove each boom section 36 carries a surface-servicing machine or unit at its free end. Support 44 is provided with a suitable conventional swivel mount 142 to which is rotatably couples a complementary swivel member 144. This member has an arcuately slotted flange 146. Member 144 carries an elongated rod designated generally 148 which includes an intermediate swivel coupling 158 of suitable conventional design from which depends a terminal end portion 152. A bolt 154 having an enlarged head 156 formed with a transverse bore 158 is secured to the end of rod portion 152 (FIG. 5). Bore 158 rotatably seats the head end of coupling member 168 which is held therein by means of a snap ring (not shown) of conventional design. The other end of member 168 is formed with an enlarged portion 162 having an opening 164.

A bracket 166 attached to the top of generally T-shaped casing or housing or chassis 168 or unit M has two spaced arms 170 provided with aligned holes 172. A unit or machine is detachably connected operatively to telescopic boom section 36 by means of a removable pin 169 passing through holes 172 and opening 164 in member 166. When so connected it is apparent that the operator of the apparatus can position a servicing machine M which he is using in any position on the surface he is working on which may be required to secure the desired results.

The angular position of a machine or unit M relative to the end of a boom 24 can be maintained fixed, if desired, by means of a lock screw 176 which extends through slot 174 in flange 146 and is threaded into bracket 178 fastened to support 44. A handle 180 carried by the head of lock screw 176 provides means for releasing or tightening screw 176 relative to flange 146 when it is desired to make a change in the adjusted position of rod 148 and the machine M carried thereby relative to the end of a boom 24.

A surface-treating or serving machine M constructed in accordance with the invention is compact, self-contained and relatively lightweight. 1t comprises a chassis or casing 168 in or on which all parts thereof are mounted in assembled operating relationship to constitute a complete machine. Its design is such that it permits equally efficient operation in any direction.

As viewed in F108. 6, 7, and 18, the front portion of chassis 168 or the T-head thereof contains the brushes 182 or other types of elongated cylindrical cleaning, polishing or servicing means which may be needed for a given job. Brushes 182 and the other means which may be used in the machine M, are readily removably mounted on the transversely extending ends of spindle 184 (FIG. 18) supported in bearings 186 in gearbox 188 attached by screws 198 to carry underside portion of chassis 168. Spindle 184 carries a gear 192 which is driven by gear 194 on the shaft 195 of air motor 196.

The elongated transversely extending portions of spindle 184 which carry the surface-servicing devices, hereinafter referred to as brushes, have elongated central bores in which are slidably mounted elongated cams 288. Each of these has an end release button 198 by means of which cams 288 can be moved inwardly in a bore 1.85 against a compression spring 282 seated at the inner end of each bore 185. When a brush 182 is to be placed in a unit M, button 198 is pressed. This action causes movement. of cam 288 inwardly against compression spring 282 and balls 2114 supported for radial free movement in openings in spindle 184 can drop into the relief portion of cam 200 (FIG. whereby brush 182 can be inserted on spindle 184 and press against a cushion spring 206 suitably carried by chassis 168 and encircling spindle 184. Upon release of button 198, cam 200 is moved in the opposite direction by spring 202 thereby camming up balls 204 against the central cylindrical paperboard or plastic core 205 of a brush 182 which locks it in operating position on spindle 184. Removal of a brush 182 from a spindle is accomplished by pulling it off its supporting spindle when button 198 is depressed.

The novel cantilever mounting of brushes 182 as set forth hereinabove makes it possible for an operator to achieve markedly superior results than heretofore possible. This is because of the manner in which the free ends of a brush can be moved into close adjacency with portions of the surface of an aircraft, such as close corners, heads of rivets, seams and bends thereof.

Air motor 196 is cylindrical and can be of any suitable conventional design. As disclosed in FIGS. 6, 7 and 9, it is mounted for operation in chassis 168 by bracket 208 and clamp 210 by screws 211 with its forward end seated in opening 212 in gearbox 188 and held therein by setscrew 218. The air connection 214 at the rear of air motor 196 is coupled to air fitting 216 which is fastened to the rear of chassis 168. This latter fitting is detachably secured to conduit 218 which is suitably connected to air supply conduit 52 (FIG. 3).

Handle 220 mounted on the top and adjacent the read end of chassis 168 provides'the main control and guidance for machine or unit M. It supports air trigger 222 which is rockably mounted on pin 224 in the handle bracket. Trigger 222 has an arm 226 at its base positioned to engage and depress valve stem 228 of a conventional type of control valve (not shown) of air motor 196 to power the motor and rotate spindle 184 and the brushes thereon.

Referring to FIGS. 6, 8 and 9, two sets of rollers are pro vided for supporting a unit or machine M with rolling contact on the surface being worked on. Forward rollers 230, which in the illustrated form of the invention are five in number, are fixed for rotation on shaft 232 supported in brackets 234 attached to the sides of chassis 168. These rollers preferably are provided with a suitable elastomeric tire 235, such as rubber, such that they will not scratch or otherwise mar the surface of the aircraft or other vehicle being processed.

Rear rollers 236, also provided with a similar elastomeric tire 237, are mounted on shaft 233 supported in the spaced depending arms 238 of yoke member 240. A stem or rod 242 attached to the center of the cross arm of yoke 240 extends upwardly through chassis 168 and projects through the top of handle 220 (FIGS. 6 and 8). A lock nut 244 is threaded on the top free end of stem 242. An adjusting nut 246 also threadably mounted on the top portion of stem 242 extends at right angles thereto through openings in the sidewalls of handle 220.

Arms 238 are formed with vertical grooves 239 extending along their outer faces. These provide for vertical sliding coaction with elongated guide members formed on the opposite inner walls of chassis 168. This construction stabilizes the rear rollers 236 in that it holds their support yoke 240 against forward or rearward motion relative to chassis 168. A spring 243 encircling stern 242 between collar 248 on stem 242 and the top of handle 220 (FIG. 8) maintains a resilient support for the rear rollers on yoke 240 on the surface being worked on, a washer 245 being disposed between the top of stem 242 and the bottom of spring 243.

By loosening locknut 244 and turning adjusting nut 246 on stem 242, the latter and therefore yoke 240 with rollers 236 can be raised or lowered as desired relative to chassis 168. After each adjustment locknut is again tightened against the top of handle 220 to secure the adjustment. TI-Iis adjustment provides the desired controlled pressure of the brushes 182 on the surface being treated. When the adjustment is made pivoting action occurs with the fixed rollers 230 acting as the center of pivotal action.

Handle 250 mounted on the top front end of chassis 168 provides the forward support for machine M, and also supports the mechanism which controls the flow of cleaning or other kind of fluid which may be required for a job to brushes 182. Referring to FIGS. 6, 7, l2 and 13, handle 250 has a central, vertical bore 252 in which a liquid release button 254 attached to the top of valve stem 256 is vertically slidably mounted. Valve stem 256 extends downwardly (FIG. 12) through guide 258 in bore 252 and valve seat 260 of valve V threadably secured in the bottom of handle 250.

As best shown in FIGS. 12 and 13, valve seat 260 is formed with a circumferential outer groove 262, a downwardly diverging central tapered bore 264 and a transverse bore 266 connecting with groove 262 and bore 264. The bottom end of stem 256 is formed with a tapered plug portion 255 which is complementary with bore 264, such that when a unit M is not in use plug 255 seats snugly in bore 264, and with washer 268 attached to the end of stem 256 prevents the flow of fluid through valve V to nozzle N.

Spring 270 in bore 272 in chassis which is coaxial with bore 252 normally maintains plug 255 seated in bore 264 and washer 268 pressed against valve seat 260, as shown in FIG. 12, except when button 254 is depressed. When this occurs valve V is opened and fluid can flow from conduit 274 through valve V, duct 276 in chassis 168, and can be delivered under pressure to the work by nozzle N, which is detachably mounted on chassis 168 and connected to duct 276.

The pattern of spray delivered from nozzle N is flat and an gular. The sprayed fluid is applied to the work ahead of a unit or machine M. The spray'nozzle is retained in place on chassis I 168 by retainer 278 and adapter 280. Nozzle N can be of any suitable conventional type and is readily removable from chassis 168 for cleaning, replacement or repair by removing retainer 278.

The desired liquid for doing a specified job, such as cleaning the surface of an airplane, is delivered under any suitable pressure from the bottom supporting system by the means described hereinabove. Such fluid is conveyed to conduit 274 from a semirigid pressure conduit 282 mounted in and extending longitudinally in chassis 168 (FIGS. 6, 7 and 9). Conduit 282 has one end removably coupled to conduit 274 and its other end similarly attached to conduit 288 by means of suitable conventional couplings 286 and 287. Couplings 287 is joined to one end of conduit 288, the other end of which is connected to conduit 54 on a boom 24 from which fluid under a desired pressure is delivered to nozzle N for discharge therefrom ahead of the servicing machine or unit M which is in use.

Referring to FIGS. 6 and 10, arcuate guards 290 may be provided if safety regulations require them. As shown, these comprise flanges 292 which are rotatably mounted on hub portions 294 of gearbox 188. Guards 290 are maintained in resiliently, frictionally operative position thereon for movement relative to chassis 168 and for movement down over and back over brushes 182 by means of snap rings 296.

As used herein the term brush is intended to mean any elongated cylindrical body surface treating means having a central core which enables it to be used in a surface-servicing machine or unit M when seated on and secured to a spindle 184 thereof. A brush 182 can be made of plastic, such as foamed or expanded polyeurathane, or an elastomeric material such as rubber, or elongated cleaning and/or polishing fibers. It may also comprise many types of bristles, or other types of suitable cleaning and/or polishing or abrading materials. In the following claims brush" defines an element mounted for rotation with spindle I84.

Brushes 182 are substantially cantileveredly carried on spindles 184. Because of this construction their free ends can be moved readily into corners and other portions heretofore difficult to reach. The extension and exposure of brushes 182 beyond the body of machine M (FIGS. 6 and 7) protects the surface of an aircraft from damage by the machine while work is in progress. The adjustable guards 290 when moved down into their operative positions protect the operator from spraying polish or cleaner fluids.

The position of nozzle N at the front end of a machine M insures the sprayed delivery of cleaning and/or polishing fluids onto the surface to be serviced in advance of the brushes 182 whenever button 254 is pressed.

in operation, it is assumed that the surface of an airplane is to be cleaned and polished. Operators place the selected type of fluid, say a polishing fluid, in container 68, and then open the valves 23 and 27 which are in the compressed air lines delivering to the fluid line and air motor of a surface-treating unit M.

This will ready the apparatus for effecting the delivery of polishing fluid to nozzle N and operate air motor 196 when their respective button 254 and trigger 222 are pressed.

As shown in FIG. 1, two operators are standing on a scaffold 70 and working on the surface of an airplane with an apparatus 2. Valve handle 9 has been manipulated to raise mast section to the selected position for doing the required work. Each operator now can grip the handles 220 and 250 of a machine or unit M supported on booms 24, position rollers 230 and 236 on the surface to be worked on and move machine M therealong. The adjusted position of movable rollers 236 determines the pressure of brushes 182 upon the surface of the aircraft being serviced. When handle or trigger 222 is pressed air motor 196 is set into operation and spindles 184 and brushes 182 thereon rotate. When handle button 254 is pressed fluid in delivered from container 68 to nozzle N and sprayed therefrom in front of brushes 182 which apply it to the aircrafts surface. Because machine M is symmetrical about its longitudinal axis it can be operated in either direction without leaving defacing marks on the surface being serviced, and due to the novel mounting of brushes 182 it is especially efficient in close comer and difficult areas of the surface.

After the polish has dried it is removed from the surface. For the next operation brushes 182 are removed from a machine M and polishing means or brushes are substituted therefor. For this operation only air motor 196 need be operated. Therefore, conduit 288 can be disconnected and line 276 to nozzle N incapacitated, since no fluid is required for the polishing operation. The operator merely operates air motor for rotating spindles 184 and the polishing brushes thereon to remove the dry polish and buff up the now clean and polished exterior surface of the airplane.

During the work on all exterior surfaces, such as vertical and underwing surfaces where an operator would have to exert great physical effort, which over a period of time could be extremely tiring, the working tool or machine M is connected to boom 24 in order to obtain the benefit of the novel counterpoise mechanism described hereinabove. However, when an operator is working on top surface portions or areas of an aircraft, e.g., the top of a wing, the counterpoise or balance mechanism need not be used. in such case, each boom 24 is maintained fully retraced as shown in FIGS. 2 and i, and held in substantially horizontal position by a locking member in torsion spring balance device 98. For this part of the work, machine M can be detached from its supporting coupling member 160 by the removal of pin 1169. The air and polish hoses 52 and 5d are removed, and in their places long air and polish hoses can be attached to manifold 46 and to a machine or unit M. This arrangement permits working at a greater distance from mast 6 when work is to be done on large top surface areas.

it will be appreciated that the provision of vertically adjustable rollers 236 in the chassis 168 of a machine M make it possible to control the pressure exerted by brushes and applicators 182 on the work. In this way means are also provided for controlling the amount of heat generated in the surface being serviced, and to hold such heat within safe limits.

What we claim is:

1. An apparatus of the type described comprising a vertically extensible mast, a support for said mast, at least one generally horizontally extending elongated boom carried at the top of said mast, a machine mounted at the free end of said boom for working on the surface of an aircraft, mechanism for raising at least a portion of said mast or lowering it to locate said boom at selected operating positions relative to the surface of said aircraft to be serviced, including means for mounting said boom on said mast including means for permitting horizontal and vertical movement of said boom with respect to said mast, wherein said means for permitting said horizontal and vertical movement are disposed on one side of said mounting means and in close proximity to one another.

2. The invention defined in claim ll, wherein said mast comprises a fixed section mounted on a platform, and a telescopic section mounted for vertical movement relative into said fixed section, pneumatically actuated mechanism for effecting the movement of said telescopic section to locate said boom at said selected operating positions, and means of controlling the operation of said mechanism and the extent of movement of said telescopic section.

3. An apparatus of the type described comprising a vertically extensible mast, a support for said mast, at least one generally horizontally extending elongated boom carried at the top of said mast, a machine mounted at the free end of said boom for working on the surface of an aircraft, mechanism for raising at least a portion of said mast or lowering it to locate said boom at selected operating positions relative to the surface of said aircraft to be serviced, including means for mounting said boom on said mast for movement in vertical and horizontal planes, wherein said boom comprises a fixed section supported on said mast by said last'named means, an extensible section having means for supporting said machine for working on the surface of said aircraft, including counterpoise mechanism for balancing said boom while an operator is working on areas of said aircraft surface, and a resilient torsional device coacting with said boom for controlling the movement of said extensible section of said boom in said fixed section thereof, and for restoring said extensible section to its withdrawn position in said fixed section when said apparatus is inoperative.

41. The invention defined in claim 3, wherein said counterpoise mechanism includes a bracket mounting a torsion spring attached to said mast and a link connected to an arm coacting with said spring and a bracket on said fixed section to which said link also is connected, and means for selectively incapacitating said counterpoise mechanism when an operator using a machine carried on the free end of said boom is working on selected generally horizontal surfaces of said aircraft.

5. An apparatus of the type described comprising a vertically extensible mast, a support for said mast, at least one generally horizontally extending elongated boom carried at the top of said mast, a machine mounted at the free end of said boom for working on the surface of an aircraft, mechanism for raising at least a portion of said mast or lowering it to locate said boom at selected operating positions relative to the surface of said aircraft to be serviced, including means for mounting said boom on said mast for movement in vertical and horizontal planes, wherein said boom comprises a fixed section supported on said mast by said last-named means, an extensible section having means for supporting said machine for working on the surface of said aircraft, wherein apparatus includes counterpoise mechanism connected to said mast and said boom for balancing said boom and tending to maintain said boom in a generally horizontal position except when said apparatus is in use, and resilient means for controlling the ex tensible movement of said extensible boom section as an operator moves said machine supported on said boom over the surface of an aircraft.

6. The invention defined in claim 5 including an auxiliary counterpoise mechanism coacting with said sections of said boom for preventing unbalance of said boom when said extensible section thereof approaches the outer limits of its extension during the operation of said apparatus.

7. The invention defined in claim 6 wherein said auxiliary counterpoise mechanism comprises a spring motor supported on said fixed section of said boom, a guide rod extending along said fixed section of said boom, brackets attached to said lastnamed boom section supporting said guide rod, a weight carriage slidably mounted on said guide rod, means connected to said spring motor, said carriage and said extensible boom section for effecting the rearward movement of said weight carriage during outward movement of said extensible boom section relative to said fixed section, and for causing the opposite movement of said carriage in response to the constant torque exerted by said spring motor when said extensible boom section is moved rearwardly relative to said fixed section of said boom, and the desired balanced condition of said boom is maintained.

8. An apparatus of the type described comprising a vertically extensible mast, a support for said mast, at least one generally horizontally extending elongated boom carried at the top of said mast, a machine mounted at the free end of said boom for working on the surface of an aircraft, mechanism for raising at least a portion of said mast or lowering it to locate said boom at selected operating positions relative to the surface of said aircraft to be serviced, including a container for surface servicing fluid materials, a nozzle on said machine, a flexible hose extending from said container upwardly relative to said mast along said boom and connected to said machine for discharge of said materials from said nozzle, a fluidoperated motor for said surface-servicing machine, rotatable brush means mounted in said machine and driven by said mtor, a flexible hose extending upwardly relative to said mast along said boom and connected to said motor for delivering compressed air thereto for driving said motor, control means for actuating said motor and effecting the flow of fluid materials from said container to said machine, and means on said machine for effecting the controlled discharge of said materials from said nozzle onto the surface of said aircraft in advance of said brush means.

9. The invention defined in claim 8, wherein said boom is mounted for angular movement relative to said mast, and said boom comprises a fixed section and an extensible section mounted for movement relative thereto, conduit means attached to the free end of said fixed boom section and connected to the ends of said hoses extending along said boom, complementary flexible pressure hoses also connected to said conduit means above said fixed boom section, guide rods ex tending along said fixed boom section, a movable bracket located above said fixed boom section, said bracket having spaced legs depending therefrom and slidably supported on said guide rods, a vertical shaft carried by said bracket, a pair of superimposed sheaves rotatably mounted on said bracket shaft, said complementary hoses being trained over said sheaves and having their other ends attached to the free end of said extensible section of said boom, a stationary bracket attached to said fixed section of said boom proximate said mast, a torsion spring mechanism mounted on said fixed bracket, a cable connecting said torsion spring mechanism to said movable bracket such that resilient pressure is constantly exerted on said movable bracket during its movement on said guide rods in response to the outward or inward travel of said extensible section of said boom, and said complementary hoses are maintained in substantially parallel relationship relative to said boom and to themselves during the operation of said apparatus and the movement of said machine along and upon the surface of the aircraft being serviced.

10. The invention defined in claim 9 including an elongated support for said servicing machine carried on the free end of said extensible section of said boom, and means for adjusting said support relative to said free end of said boom section to dispose said machine in a selected operating position.

11. An apparatus of the type described comprising a vertically extensible mast, a support for said mast, at least one generally horizontally extending elongated boom carried at the top of said mast, a machine mounted at the free end of said boom for working on the surface of an aircraft, mechanism for raising at least a portion of said mast or lowering it to locate said boom at selected operating positions relative to the surface of said aircraft to be serviced, wherein said machine is provided with a chassis, an air motor mounted in said chassis, brush means having a fixed end rotatably supported in said chassis and a free end thereof extending transversely outwardly therefrom, tranversely mounted spindles mounted in said chassis supporting said brush means, a nozzle mounted at the front end of said chassis, pressure hoses for conducting compressed air to said motor for driving said motor and rotating said brush means, and conduits for delivering cleaning and/or polishing materials to said nozzle for discharge therefrom onto the surface of said aircraft being treated in ad vance of said brush means.

12. An apparatus of the type described comprising a vertically extensible mast, a support for said mast, at least one generally horizontally extending elongated boom carried at the top of said mast, a machine mounted at the free end of said boom for working on the surface of an aircraft, mechanism for raising at least a portion of said mast or lowering it to locate said boom at selected operating positions relative to the surface of said aircraft to be serviced, wherein said machine comprises a chassis, brush means rotatably mounted in said chassis and extending transversely outwardly from the sides of said chassis and partially below the bottom edge thereof, a motor mounted in said chassis for driving said brush means, a transverse shaft extending between the sides of said chassis and substantially intermediate of its length, rollers mounted on said shaft, a vertically movable yoke having laterally spaced downwardly extending arms, means mounting said yoke in said chassis rearwardly of said rollers and adjacent the rear end of said chassis, a shaft supported in said arms of said yoke, rollers mounted on said shaft, and means for adjusting the position of said yoke vertically in said chassis and said rollers carried thereby for disposing said rollers in a selected operating position for movement of said machine on said rollers over the surface to be serviced.

13. The invention defined in claim 1, wherein said means for mounting said boom on said mast for movement in vertical and horizontal planes are separate and distinct from one another and disposed in immediate adjacent relationship to one another.

14. The invention defined in claim 13, wherein said lastmentioned means are disposed in abutting relationship.

15. An apparatus of the type described comprising a vertically extensible mast, a support for said mast, at least one generally horizontally extending elongated boom carried at the top of said mast, a machine mounted at the free end of said boom for working on the surface of an aircraft, mechanism for raising at least a portion of said mast or lowering it to locate said boom at selected operating positions relative to the surface of said aircraft to be serviced, wherein said top of said mast is provided with a bracket, a yoke mounted on said bracket, said yoke having upstanding arms, and wherein an elongated boom is carried on each of said arms, and each of said booms is movable independent of the other.

16. An apparatus of the type described comprising a vertically extensible mast, a support for said mast, a yoke carried at the top of said mast having a plurality of spaced arms, a plurality of horizontally extending elongated booms carried at the top of said mast, a machine mounted at the free end of said booms for working on the surface of an aircraft, mechanism for raising at least a portion of said mast or lowering it to locate said booms at selected operating positions relative to the surface of said aircraft to be serviced, wherein each of said booms include mounting means supporting it on an arm of said yoke for movement in horizontal and vertical planes.

17. The invention defined in claim 16, wherein each of said booms includes a fixed section and an extensible section supporting said servicing machine for movement over the surface of an aircraft for cleaning and/or polishing said surface. 

1. An apparatus of the type described comprising a vertically extensible mast, a support for said mast, at least one generally horizontally extending elongated boom carried at the top of said mast, a machine mounted at the free end of said boom for working on the surface of an aircraft, mechanism for raising at least a portion of said mast or lowering it to locate said boom at selected operating positions relative to the surface of said aircraft to be serviced, including means for mounting said boom on said mast including means for permitting horizontal and vertical movement of said boom with respect to said mast, wherein said means for permitting said horizontal and vertical movement are disposed on one side of said mounting means and in close proximity to one another.
 2. The invention defined in claim 1, wherein said mast comprises a fixed section mounted on a platform, and a telescopic section mounted for vertical movement relative to said fixed section, pneumatically actuated mechanism for effecting the movement of said telescopic section to locate said boom at said selected operating positions, and means of controlling the operation of said mechanism and the extent of movement of said telescopic section.
 3. An apparatus of the type described comprising a vertically extensible mast, a support for said mast, at least one generally horizontally extending elongated boom carried at the top of said mast, a machine mounted at the free end of said boom for working on the surface of an aircraft, mechanism for raising at least a portion of said mast or lowering it to locate said boom at selected operating positions relative to the surface of said aircraft to be serviced, including means for mounting said boom on said mast for movement in vertical and horizontal planes, wherein said boom comprises a fixed section supported on said mast by said last-named means, an extensible section having means for supporting said machine for working on the surface of said aircraft, including counterpoise mechanism for balancing said boom while an operator is working on areas of said aircraft surface, and a resilient torsional device coacting with said boom for controlling the movement of said extensible section of said boom in said fixed section thereof, and for restoring said extensible section to its withdrawn position in said fixed section when said apparatus is inoperative.
 4. The invention defined in claim 3, wherein said counterpoise mechanism includes a bracket mounting a torsion spring attached to said mast and a link connected to an arm coacting with said spring and a bracket on said fixed section to which said link also is connected, and means for selectively incapacitating said counterpoise mechanism when an operator using a machine carried on the free end of said boom is working on selected generally horizontal surfaces of said aircraft.
 5. An apparatus of the type described comprising a vertically extensible mast, a support for said mast, at least one generally horizontally extending elongated boom carried at the top of said mast, a machine mounted at the free end of said boom for working on the surface of an aircraft, mechanism for raising at least a portion of said mast or lowering it to locate said boom at selected operating positions relative to the surface of said aircraft to be serviced, including means for mounting said boom on said mast for movement in vertical and horizontal planes, wherein said boom comprises a fixed section supported on said mast by said last-named means, an extensible section having means for supporting said machine for working on the surface of said aircraft, wherein apparatus includes counterpoise mechanism connected to said mast and said boom for balancing said boom and tending to maintain said boom in a generally horizontal position except when said apparatus is in use, and resilient means for controlling the extensible movement of said extensible boom section as an operator moves said machine supported on said boom over the surface of aN aircraft.
 6. The invention defined in claim 5 including an auxiliary counterpoise mechanism coacting with said sections of said boom for preventing unbalance of said boom when said extensible section thereof approaches the outer limits of its extension during the operation of said apparatus.
 7. The invention defined in claim 6 wherein said auxiliary counterpoise mechanism comprises a spring motor supported on said fixed section of said boom, a guide rod extending along said fixed section of said boom, brackets attached to said last-named boom section supporting said guide rod, a weight carriage slidably mounted on said guide rod, means connected to said spring motor, said carriage and said extensible boom section for effecting the rearward movement of said weight carriage during outward movement of said extensible boom section relative to said fixed section, and for causing the opposite movement of said carriage in response to the constant torque exerted by said spring motor when said extensible boom section is moved rearwardly relative to said fixed section of said boom, and the desired balanced condition of said boom is maintained.
 8. An apparatus of the type described comprising a vertically extensible mast, a support for said mast, at least one generally horizontally extending elongated boom carried at the top of said mast, a machine mounted at the free end of said boom for working on the surface of an aircraft, mechanism for raising at least a portion of said mast or lowering it to locate said boom at selected operating positions relative to the surface of said aircraft to be serviced, including a container for surface servicing fluid materials, a nozzle on said machine, a flexible hose extending from said container upwardly relative to said mast along said boom and connected to said machine for discharge of said materials from said nozzle, a fluid-operated motor for said surface-servicing machine, rotatable brush means mounted in said machine and driven by said motor, a flexible hose extending upwardly relative to said mast along said boom and connected to said motor for delivering compressed air thereto for driving said motor, control means for actuating said motor and effecting the flow of fluid materials from said container to said machine, and means on said machine for effecting the controlled discharge of said materials from said nozzle onto the surface of said aircraft in advance of said brush means.
 9. The invention defined in claim 8, wherein said boom is mounted for angular movement relative to said mast, and said boom comprises a fixed section and an extensible section mounted for movement relative thereto, conduit means attached to the free end of said fixed boom section and connected to the ends of said hoses extending along said boom, complementary flexible pressure hoses also connected to said conduit means above said fixed boom section, guide rods extending along said fixed boom section, a movable bracket located above said fixed boom section, said bracket having spaced legs depending therefrom and slidably supported on said guide rods, a vertical shaft carried by said bracket, a pair of superimposed sheaves rotatably mounted on said bracket shaft, said complementary hoses being trained over said sheaves and having their other ends attached to the free end of said extensible section of said boom, a stationary bracket attached to said fixed section of said boom proximate said mast, a torsion spring mechanism mounted on said fixed bracket, a cable connecting said torsion spring mechanism to said movable bracket such that resilient pressure is constantly exerted on said movable bracket during its movement on said guide rods in response to the outward or inward travel of said extensible section of said boom, and said complementary hoses are maintained in substantially parallel relationship relative to said boom and to themselves during the operation of said apparatus and the movement of said machine along and upon the surface of the aircraft being serViced.
 10. The invention defined in claim 9 including an elongated support for said servicing machine carried on the free end of said extensible section of said boom, and means for adjusting said support relative to said free end of said boom section to dispose said machine in a selected operating position.
 11. An apparatus of the type described comprising a vertically extensible mast, a support for said mast, at least one generally horizontally extending elongated boom carried at the top of said mast, a machine mounted at the free end of said boom for working on the surface of an aircraft, mechanism for raising at least a portion of said mast or lowering it to locate said boom at selected operating positions relative to the surface of said aircraft to be serviced, wherein said machine is provided with a chassis, an air motor mounted in said chassis, brush means having a fixed end rotatably supported in said chassis and a free end thereof extending transversely outwardly therefrom, tranversely mounted spindles mounted in said chassis supporting said brush means, a nozzle mounted at the front end of said chassis, pressure hoses for conducting compressed air to said motor for driving said motor and rotating said brush means, and conduits for delivering cleaning and/or polishing materials to said nozzle for discharge therefrom onto the surface of said aircraft being treated in advance of said brush means.
 12. An apparatus of the type described comprising a vertically extensible mast, a support for said mast, at least one generally horizontally extending elongated boom carried at the top of said mast, a machine mounted at the free end of said boom for working on the surface of an aircraft, mechanism for raising at least a portion of said mast or lowering it to locate said boom at selected operating positions relative to the surface of said aircraft to be serviced, wherein said machine comprises a chassis, brush means rotatably mounted in said chassis and extending transversely outwardly from the sides of said chassis and partially below the bottom edge thereof, a motor mounted in said chassis for driving said brush means, a transverse shaft extending between the sides of said chassis and substantially intermediate of its length, rollers mounted on said shaft, a vertically movable yoke having laterally spaced downwardly extending arms, means mounting said yoke in said chassis rearwardly of said rollers and adjacent the rear end of said chassis, a shaft supported in said arms of said yoke, rollers mounted on said shaft, and means for adjusting the position of said yoke vertically in said chassis and said rollers carried thereby for disposing said rollers in a selected operating position for movement of said machine on said rollers over the surface to be serviced.
 13. The invention defined in claim 1, wherein said means for mounting said boom on said mast for movement in vertical and horizontal planes are separate and distinct from one another and disposed in immediate adjacent relationship to one another.
 14. The invention defined in claim 13, wherein said last-mentioned means are disposed in abutting relationship.
 15. An apparatus of the type described comprising a vertically extensible mast, a support for said mast, at least one generally horizontally extending elongated boom carried at the top of said mast, a machine mounted at the free end of said boom for working on the surface of an aircraft, mechanism for raising at least a portion of said mast or lowering it to locate said boom at selected operating positions relative to the surface of said aircraft to be serviced, wherein said top of said mast is provided with a bracket, a yoke mounted on said bracket, said yoke having upstanding arms, and wherein an elongated boom is carried on each of said arms, and each of said booms is movable independent of the other.
 16. An apparatus of the type described comprising a vertically extensible mast, a support for said mast, a yoke carried at the top of said mast havIng a plurality of spaced arms, a plurality of horizontally extending elongated booms carried at the top of said mast, a machine mounted at the free end of said booms for working on the surface of an aircraft, mechanism for raising at least a portion of said mast or lowering it to locate said booms at selected operating positions relative to the surface of said aircraft to be serviced, wherein each of said booms include mounting means supporting it on an arm of said yoke for movement in horizontal and vertical planes.
 17. The invention defined in claim 16, wherein each of said booms includes a fixed section and an extensible section supporting said servicing machine for movement over the surface of an aircraft for cleaning and/or polishing said surface. 